JPH10163619A - Method for mounting ic package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for mounting an IC package which prevents the short circuit and poor contact between leads of soldering, improves the soldering reliability, and reduces the work time. SOLUTION: The method comprises steps S210 of removing foreign substances on a PCB, S230 of coating a flux on a lead pattern formed on the PCB, S240 of arranging leads of an IC package on the flux-coated lead pattern of the PCB, S250 of covering a semiconductor chip of the IC package with a holding block and irradiating a light beam on the entire surface to solder the leads to the lead pattern, and S260 of cooling the soldered PCB and holding block.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a printed circuit board (PC).
B) Tape CarrierPackag
e: TCP).

[0002]

2. Description of the Related Art With the development of semiconductor technology, ICs used in electronic products are becoming more sophisticated and highly integrated. Along with this, IC packages for heat control of ICs have been developed. As ICs become more sophisticated, the number of pads increases, the number of leads in the package also increases, and the lead density increases. Therefore, research on a technology for mounting a package on a PCB has been advanced.

Recently, high performance has been demanded even for small computers such as notebook computers. In the case of a notebook computer, since the product is characterized by its small size and light weight, the smaller the IC package to be mounted, the better.

[0004] TCP is a high-fine component having a lead interval of 0.25 mm, and has no wire bonding used in a general semiconductor chip and can be made small, so that the PCB can be formed small.

FIG. 7 is a partially broken perspective view of the TCP.

[0006] In the TCP, the semiconductor chip 100 is placed at the center of the polyimide film 103.
It is placed up and down with respect to. Semiconductor chip 100
Lead 102 adhered to the polyimide film 10
3, a pattern is formed on the chip surface side to maintain insulation between the leads, and is protected from external impact. Further, in the polyimide film 103, a slot 106 is opened at a position spaced apart from each edge of the semiconductor chip 100 by a predetermined distance so as to face the edge, and a part of the lead 102 is exposed.

A conventional method of mounting the TCP having such a configuration on a PCB will be described as follows.

First, with the PCB fixed, a flux is uniformly applied on a lead pattern of the PCB on which the TCP leads are mounted. Here, after the TCP cut / shaped in another process is placed so that the lead and the lead pattern on the PCB correspond to each other, the TCP lead is heated and pressed to apply the TCP lead to the lead pattern on the PCB. Implement Next, the soldered PCB is cooled and removed from the tray.

On the other hand, in the step of cutting / shaping a TCP lead, the TCP is taken into a cutting / shaping section and cut by a cutting / shaping device so as to conform to a lead pattern on a PCB. More specifically, the TCP transferred to the cutting / shaping unit is cut by the cutting / shaping device along the line AA 'in FIG.

FIG. 8 is a cross-sectional view of the TCP cut along the line AA 'of FIG. 7 and soldered. FIG. 9 is a cross-sectional view for explaining a method of attaching a heat sink to the TCP.

Referring to FIG. 8, a cut is made to include the polyimide film 103 ′ outside the slot 106. Thereafter, the cut lead is immediately shaped into a predetermined shape by a cutting / shaping device to be a lead shape conforming to a lead pattern in the PCB.

Referring to FIG. 9, in the conventional mounting method, the PCB has a heat sink 130 for releasing heat when the semiconductor chip 100 is operated. Opening 116
have. Since the back surface of the semiconductor chip 100 protrudes from the polyimide film 103, conductive adhesive pads 113 and 113 ′ are attached to this protruding portion and the heat sink 130, and the protruding portion (back surface) of the semiconductor chip 100 is attached to the opening 116 of the PCB. Insert the heat sink 13 from the opposite direction.
0 is mounted on the semiconductor chip 100.

[0013]

However, according to the conventional mounting method, when the TCP leads are crimped at the soldering stage, the alignment of the leads may be disturbed, which may cause a short circuit between adjacent leads. There is. Further, when a pressure is directly applied to the lead by the hot bar, the lead itself is thin and damaged because of the thinning, and the life of the lead may be shortened or a contact failure may occur even when soldering is performed. In addition, mounting the heat sink with the conventional structure requires a long time and is difficult to perform.

[0014]

According to the present invention, there is provided a method of mounting a TCP type IC package on a printed circuit board (PCB), comprising the steps of: Applying flux to the lead pattern formed on the substrate, aligning the leads of the IC package on the lead pattern on the PCB to which the flux has been applied, and covering the semiconductor chip portion of the aligned IC package with a holding block. A method of mounting an IC package, comprising: irradiating a light beam onto the entire surface to solder the leads and the lead pattern; and cooling the soldered PCB and holding block. Before applying the flux, the method includes applying a conductive bond to a portion of the IC package where the semiconductor chip is located. The conductive bond is applied over an area of 60% of the semiconductor chip size, and the conductive bond is also applied to the back side of the PCB through via holes formed in the PCB. This PC
A heat sink is attached via the conductive bond applied to the back surface of B. The flux is applied by a nozzle. The flux is applied using a stamp engraved with a lead pattern. The PCB is fixed by the magnetic material attached to the holding block and the magnet of the magnet fixing jig. The IC package is mounted on the PCB based on the recognition mark on the PCB. Soldering is performed using a xenon (Xe) light beam. After sucking the IC package through the holding block, the leads of the IC package are aligned on the lead pattern on the PCB.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail.

FIG. 1 is a block diagram showing a TCP mounting system according to the present invention. The mounting system includes a loading unit 10 for loading a PCB into a mounting system,
A dispenser unit 20 for applying a conductive bond to a portion corresponding to the TCP back surface of the CB, a cutting / shaping unit 30 for cutting the TCP to a predetermined size to shape the lead, and a PCB for applying the conductive bond to the PCB. A mounting part 40 for aligning the TCP leads formed by applying a flux to the TCP lead pattern with the lead patterns of the PCB;
It comprises a soldering unit 50 for soldering the TCP mounted on the CB with a xenon (Xe) light beam, and a cooling unit 60 for cooling the soldered PCB.

FIG. 2 is a flowchart of a TCP mounting process.
FIG. 3 is a view of a TCP lead cutting process, FIG. 4A is a perspective view of a holding block, FIG. 4B is a partially broken perspective view when the holding block is positioned on the TCP, and FIG. 5A is a magnet fixing jig with a PCB mounted thereon. Sectional view of FIG. 5B
Fig. 6 is a perspective view of a magnet fixing jig, and Fig. 6 is a PC on which TCP is mounted.
FIG. 3B is a diagram when a heat sink is attached to B.

Hereinafter, the process of mounting TCP will be described in detail. In the following embodiment, the PCB is composed of four PCBs.
Are combined in an array.

As shown in the flow chart of FIG.
Four PCBs 110 supplied to the loading unit 10 in the stage
In step S210, contaminants attached to the surface are removed. Next, the PCB 110 is placed on the magnet fixing jig 120 shown in FIGS. 5A and 5B.

The magnet fixing jig 120 is a flat plate 122
And support legs 124 formed at each vertex of the flat plate 122. 4 on the flat plate 122
There are four openings 128 corresponding to the one PCB 110, and the openings 128 correspond to the lead pattern portion of the PCB 110. At the four corners of each opening 128, magnets 126 for fixing the holding block 150 are buried at a depth so as to be flush with the surface of the flat plate 122. PCB 110 placed in this opening
As shown in FIG. 4B, there is a pair of recognition marks 115 in a diagonal direction,
Is a reference mark when mounting on the PCB 110.

After fixing the PCB 110 on the magnet fixing jig 120, the conductive bond 114 is attached to the PCB 11 by the dispenser installed in the dispenser section 20 in step S220.
A predetermined area is applied from the central portion of the region where the TCP semiconductor chip 100 on the top 0 is seated. The area to be applied is preferably applied to a portion corresponding to an area of 60% of the area of the semiconductor chip 100.

As shown in FIG. 6, a portion of the PCB 110 where the conductive bond 114 is applied is provided with a via hole.
(Through hole) 118 is formed, and the conductive bond 1
14 is also applied to the back surface of PCB 110 through via hole 118. The conductive bond 114 ′ applied to the back side of the PCB 110 allows the heat sink 130 to
To dissipate the heat generated during operation of the semiconductor chip 110.

That is, according to the present invention, the heat sink 13
There is no need to form an opening in the PCB 110 to attach the zeros, and the conductive bond 114 'applied to the back surface allows the heat sink 130 to be attached to the PCB 110, facilitating the work. In addition, the applied conductive bond 114 is formed between the TCP semiconductor chip 100 and the PCB 1 for the TCP lead 102 to be bent at the time of shaping.
10 is compensated for, so that the mounting stability of the TCP is improved. The conductive bond 114 is applied to the other three PCBs 110 in the same manner.

Next, in step S230, the flux of the solid powder is uniformly applied to the lead pattern on the PCB 110 by the nozzle. At this time, the flux can be quickly and uniformly applied by applying a flux to the stamp engraved with the TCP lead pattern and pressing the stamp onto the lead pattern on the PCB 110. The flux is used as a lubricant to facilitate soldering in the next soldering step. The PCB 110 to which the flux has been applied is transferred to the mount unit 40 on which the camera is mounted so that the lead pattern 330 on the PCB 110 can be enlarged and monitored.

On the other hand, the TCP captured by the cutting / shaping unit 30 in step S300 is cut / shaped to a size suitable for the lead pattern 330 on the PCB 110 in step S310. Specifically, as shown in FIGS. 3A and 3B, the cutting / shaping apparatus 160 cuts a large number of leads 102 at the same time near the outer end in the slot 106. At this time, the polyimide film 103 outside the slot 106 is not included. Next, the lead 102 cut as shown in FIG. 3C is immediately cut by the cutting / shaping device 160 into the PCB 11.
It is shaped into a form having a predetermined curvature so as to be joined to zero. The cut / shaped TCP is transferred to and attached to the lead pattern 330 on the PCB 110 installed in the mount unit 40 in step S240.

At this time, the holding block 15
0 is adsorbed by the vacuum pump and transferred onto the TCP. As shown in FIG. 4A, the holding block 15
Reference numeral 0 denotes a quadrilateral having a predetermined thickness corresponding to the shape of the TCP semiconductor chip 100, and a TCP located in the inside of the holding block 150 is adsorbed at the center using a vacuum pump installed in the mounting system. Ho so you can
Is opened. At this time, a positioning groove for the TCP semiconductor chip 100 is formed on the back surface of the holding block 150, so that the TCP can be stably adsorbed. In addition, supporting portions 1 are provided at four corners of the holding block 150.
A magnetic body 156 having a predetermined thickness is attached to a lower portion of the support 152 as shown in FIG. 5A. The magnetic material 156 is used for the magnet 126 during the mounting stage.
Holding block 15
0 is fixed.

Attachment can be performed automatically or manually based on TCP and PCB camera images. That is,
Using the recognition mark 115 on the PCB 110, the position of the PCB 110 fixed to the magnet fixing jig 120 is confirmed, and the TCP leads 102 are accurately aligned on the lead pattern 330 on the PCB 110.

When the leads 102 are aligned, as shown in FIG. 4B, the vacuum pump is operated to be positioned on the lead pattern 330 on the PCB 110 together with the holding block 150 to which TCP has been adsorbed. Then, as shown in FIG. 5A, the magnetic body 156 attached to the lower portion of the support portion 152 of the holding block 150 and the four magnets 126 embedded in the magnet fixing jig 120 attract and are fixed, and the PCB 110 located between them is fixed. Is also fixed. Accordingly, it is possible to prevent the holding block 150 from being twisted when the TCP is positioned on the PCB 110. After the TCP leads 102 are aligned with the lead patterns 330 on the PCB 110, the PCB 110 on which the holding block 150 and the TCP are located is moved to the soldering unit 50, and the process proceeds to step S250.

In step S250, xenon (Xe) is applied to the holding block 150 of the soldering unit and the TCP.
The soldering is performed at about 300 ° C. by irradiating a light beam. At this time, soldering is performed uniformly to irradiate the entire lead pattern on the PCB 110 with the light beam.

The PCB 110 that has been soldered is
In operation S260, the PCB 110 and the holding block 150, which have been transferred to the cooling unit 60 and have been heated to a high temperature by soldering, are cooled. Then, in step S270, the holding block 150 is moved to the PCB by a vacuum pump.
Removed from 110, the process is repeated for the other three PCBs.

[0031]

According to the mounting method of the present invention as described above, since soldering is performed without directly applying pressure, there is no damage to the leads and no failure occurs after work. Also, by performing the light beam soldering, the quality of the soldering is improved, and since the leads are not pressed during the soldering, there is an effect that the reliability of the TCP after mounting is improved. Further, when soldering, since all the leads are soldered at the same time, the work time can be reduced. Also, by applying a conductive bond to a position on the printed circuit board where the TCP is to be mounted, when mounting the TCP on the PCB,
The spacing between the PCB and the semiconductor chip due to the shaped leads compensates for the mounting stability of the TCP and eliminates the need for forming an opening in the PCB for attaching a heat sink, and the conductivity applied on the back surface The work is facilitated by attaching the heat sink to the PCB via a bond.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a mounting system according to the present invention.

FIG. 2 is a flowchart of the process of the present invention.

FIGS. 3A, 3B and 3C show TCP lead cutting / cutting according to the present invention.
Shaping process diagram.

FIG. 4 is a perspective view of the holding block, and FIG. 4B is a partially broken perspective view of the holding block located on the TCP.

FIG. 5 is a sectional view of a magnet fixing jig on which a PCB is mounted, and FIG. 5B is a perspective view of the magnet fixing jig.

FIG. 6 is a cross-sectional view in which a heat sink is mounted on the PCB of the present invention.

FIG. 7 is a perspective view of a partially broken TCP.

FIG. 8 is a cross-sectional view of the soldered TCP cut along the line AA ′ of FIG. 7;

FIG. 9 is a cross-sectional view of a conventional PCB with a heat sink mounted thereon.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Loader part 20 Dispenser part 30 Cutting and shaping part 40 Mounting part 50 Soldering part 60 Cooling part 100 Semiconductor chip 102 Lead 103, 103 'Polyimide film 106 Slot 110 PCB 113, 113' Conductive adhesive pad 114, 114 ' Conductive bond 116, 128 Opening 115 Recognition mark 118 Via hole 120 Magnet fixing jig 122 Flat plate 124 Support leg 126 Magnet 130 Heat sink 150 Holding block 156 Magnetic body

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor U Pyeong-woo 733 No. zaongwon-dong, Chang'an-Gu, Suwon-si, Gyeonggi-do, Republic of Korea No. 6 (72) Inventor Masaharu 210 Umenada-dong, Paldal-gu, Suwon-shi, Gyeonggi-do, Republic of Korea No.1 Contemporary Apartment 103 Dong 1403

Claims (12)

[Claims] In a method of mounting a TCP type IC package on a printed circuit board (PCB), a step of removing foreign substances on the PCB, a step of applying a flux to a lead pattern formed on the PCB, and a step of mounting the IC package Aligning the lead on the lead pattern on the flux-coated PCB, and covering the aligned semiconductor chip portion of the IC package with a holding block and irradiating the entire surface with a light beam to separate the lead and the lead pattern. A method of mounting an IC package, comprising: soldering; and cooling a soldered PCB and a holding block. 2. The method of claim 1, further comprising applying a conductive bond to a portion of the IC package where the semiconductor chip is located before applying the flux. 3. The IC of claim 2, wherein the conductive bond is applied over an area that is 60% of the size of the semiconductor chip.
Package mounting method. 4. The conductive bond is applied to the back surface of the PCB through a via hole formed in the PCB.
The mounting method of the described IC package. 5. The IC according to claim 4, wherein the heat sink is attached via a conductive bond applied to the back surface of the PCB.
Package mounting method. 6. The IC package mounting method according to claim 1, wherein the flux is applied by a nozzle. 7. The IC package mounting method according to claim 1, wherein the flux is applied by using a stamp engraved with a lead pattern. 8. The IC package mounting method according to claim 1, wherein the PCB is fixed using a magnet fixing jig. 9. The IC package mounting method according to claim 8, wherein the PCB is fixed by a magnetic material attached to the holding block and a magnet of a magnet fixing jig. 10. The method according to claim 1, further comprising the steps of:
2. The method according to claim 1, wherein the C package is mounted on a PCB.
C package mounting method. 11. The IC package mounting method according to claim 1, wherein the soldering is performed by using a xenon (Xe) light beam. 12. I through a holding block.
2. The IC according to claim 1, wherein after adsorbing the C package, the leads of the IC package are aligned on a lead pattern on the PCB.
Package mounting method.